Recently, environmental issues such as the destruction of the ozone layer and global warming, which are influenced by Chloro Fluoro Carbons (CFCs), are receiving close attention. For this reason, reduction in the use of CFCs as a foaming agent has become a very important issue.
Therefore, since hard urethane foam is the leading foamed thermal-insulating material, it is proposed to use a hydrocarbon foaming agent which does not include a halogen molecule.
However, a hydrocarbon is not easily applied as a foaming agent because of combustibility safety, thermal-insulating efficiency quality, and so on. Further, a foamed thermal-insulating material made using a hydrocarbon as a foaming agent is less effective than the foamed thermal-insulating material made by using the present CFC11 foaming agent.